Commit 409d6f52 authored by Chuck Lever's avatar Chuck Lever
Browse files

NFSD: Free async copy information in nfsd4_cb_offload_release() 



RFC 7862 Section 4.8 states:

> A copy offload stateid will be valid until either (A) the client
> or server restarts or (B) the client returns the resource by
> issuing an OFFLOAD_CANCEL operation or the client replies to a
> CB_OFFLOAD operation.

Currently, NFSD purges the metadata for an async COPY operation as
soon as the CB_OFFLOAD callback has been sent. It does not wait even
for the client's CB_OFFLOAD response, as the paragraph above
suggests that it should.

This makes the OFFLOAD_STATUS operation ineffective during the
window between the completion of an asynchronous COPY and the
server's receipt of the corresponding CB_OFFLOAD response. This is
important if, for example, the client responds with NFS4ERR_DELAY,
or the transport is lost before the server receives the response. A
client might use OFFLOAD_STATUS to query the server about the still
pending asynchronous COPY, but NFSD will respond to OFFLOAD_STATUS
as if it had never heard of the presented copy stateid.

This patch starts to address this issue by extending the lifetime of
struct nfsd4_copy at least until the server has seen the client's
CB_OFFLOAD response, or the CB_OFFLOAD has timed out.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 62a8642b

fs/nfsd/nfs4proc.c

+10 −7
Original line number Diff line number Diff line
@@ -57,6 +57,8 @@ module_param(inter_copy_offload_enable, bool, 0644); 
MODULE_PARM_DESC(inter_copy_offload_enable,

		 "Enable inter server to server copy offload. Default: false");



static void cleanup_async_copy(struct nfsd4_copy *copy);



#ifdef CONFIG_NFSD_V4_2_INTER_SSC

static int nfsd4_ssc_umount_timeout = 900000;		/* default to 15 mins */

module_param(nfsd4_ssc_umount_timeout, int, 0644);
@@ -1602,8 +1604,10 @@ static void nfsd4_cb_offload_release(struct nfsd4_callback *cb) 
{

	struct nfsd4_cb_offload *cbo =

		container_of(cb, struct nfsd4_cb_offload, co_cb);

	struct nfsd4_copy *copy =

		container_of(cbo, struct nfsd4_copy, cp_cb_offload);



	kfree(cbo);

	cleanup_async_copy(copy);

}



static int nfsd4_cb_offload_done(struct nfsd4_callback *cb,
@@ -1736,11 +1740,7 @@ static void cleanup_async_copy(struct nfsd4_copy *copy) 


static void nfsd4_send_cb_offload(struct nfsd4_copy *copy)

{

	struct nfsd4_cb_offload *cbo;



	cbo = kzalloc(sizeof(*cbo), GFP_KERNEL);

	if (!cbo)

		return;

	struct nfsd4_cb_offload *cbo = &copy->cp_cb_offload;



	memcpy(&cbo->co_res, &copy->cp_res, sizeof(copy->cp_res));

	memcpy(&cbo->co_fh, &copy->fh, sizeof(copy->fh));
@@ -1790,10 +1790,13 @@ static int nfsd4_do_async_copy(void *data) 
	}



do_callback:

	/* The kthread exits forthwith. Ensure that a subsequent

	 * OFFLOAD_CANCEL won't try to kill it again. */

	set_bit(NFSD4_COPY_F_STOPPED, &copy->cp_flags);



	set_bit(NFSD4_COPY_F_COMPLETED, &copy->cp_flags);

	trace_nfsd_copy_async_done(copy);

	nfsd4_send_cb_offload(copy);

	cleanup_async_copy(copy);

	return 0;

}

fs/nfsd/xdr4.h

+3 −0
Original line number Diff line number Diff line
@@ -700,6 +700,9 @@ struct nfsd4_copy { 
	struct nfsd42_write_res	cp_res;

	struct knfsd_fh		fh;



	/* offload callback */

	struct nfsd4_cb_offload	cp_cb_offload;



	struct nfs4_client      *cp_clp;



	struct nfsd_file        *nf_src;